Low-shrinkage photocurable material and manufacturing method thereof

ABSTRACT

A low-shrinkage photocurable material is provided in the present disclosure. The low-shrinkage photocurable material includes an acrylonitrile butadiene styrene resin, a carbon black and a dispersant. The carbon black and the dispersant are mixed with the acrylonitrile butadiene styrene resin. The weight percentage of the acrylonitrile butadiene styrene resin is 85%-99.45%, the weight percentage of the carbon black is 0.05%-5%, and the weight percentage of the dispersant is 0.5%-10%.

RELATED APPLICATIONS

This application claims priority to Taiwan Application Serial Number109118490, filed Jun. 2, 2020, which is herein incorporated byreference.

BACKGROUND Technical Field

The present disclosure relates to a 3D-printed material. Moreparticularly, the present disclosure relates to a photocurable3D-printed material which can reduce the shrinkage of the product afterpost-curing.

Description of Related Art

3D printing, as the name suggests, is a technique for printingthree-dimensional objects. Basically, computers are used to divide athree-dimensional virtual model into a multiple-layered structure, andthe 3D printer can laminate the printing material according to themultiple-layered structure and create a physical three-dimensionalmodel. There are three major techniques of 3D printing, which are fuseddeposition modeling, stereolithography and selective laser sintering.Among of them, stereolithography has higher accuracy and is suitable formanufacturing more complex models. Therefore, stereolithography iswidely adopted by industries which need high accuracy for models, suchas industrial design, product design, biomedicine and jewelryindustries.

Stereolithography is based on the principle of photosensitive materialscan be polymerized into solids after being exposed to light. Duringstereolithography 3D printing, light shines on the photosensitivematerials according to one of the layered structures, which are dividedfrom the three-dimensional virtual model. Polymerization occurs in theexposed photosensitive materials, and the exposed photosensitivematerials will be cured into a structural layer. After finishing onestructural layer, the platform which supports the three-dimensionalmodel will vertically move a distance of the height of the structurallayer. A new structural layer is formed by exposure again after thephotosensitive materials cover the surface of the aforementionedstructural layer, and the new structural layer will firmly bond to theformer structural layer. In this regard, the physical three-dimensionalmodel will be formed.

Because the physical three-dimensional model is not fully cured afterprinted, a post-curing process should be performed to increase thedegree of curing of the photosensitive materials in the physical model,so as to obtain a product with more stable structure. However, thematerials with higher degree of curing will become brittle and easilybroken because of over exposure after the post-curing process, and theoverall ductility and malleability of the product will be decreased.Further, the volume of the photosensitive materials may obviously changein the post-curing process, making the product shrink and deform.

In this regard, it is still an unsolved problem to enhance the ductilityand malleability of the physical three-dimensional model after postcuring and reduce the shrinkage thereof.

SUMMARY

According to an aspect of the present disclosure, a low-shrinkagephotocurable material includes an acrylonitrile butadiene styrene resin,a carbon black and a dispersant. The carbon black and the dispersant aremixed with the acrylonitrile butadiene styrene resin. The weightpercentage of the acrylonitrile butadiene styrene resin is 85%-99.45%,the weight percentage of the carbon black is 0.05%-5%, and the weightpercentage of the dispersant is 0.5%-10%.

According to another aspect of the present disclosure, a manufacturingmethod of a low-shrinkage photocurable material includes steps asfollows. An acrylonitrile butadiene styrene resin is provided, a carbonblack solution is provided and a mixing step is performed. The carbonblack solution includes a carbon black, a dispersant and a solvent. Inthe mixing step, the acrylonitrile butadiene styrene resin and thecarbon black solution are mixed, to obtain the low-shrinkagephotocurable material. The weight percentage of the acrylonitrilebutadiene styrene resin is 85%-99.45%, the weight percentage of thecarbon black is 0.05%-5%, and the weight percentage of the dispersant is0.5%-10%.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure can be more fully understood by reading thefollowing detailed description of the embodiment, with reference made tothe accompanying drawings as follows:

FIG. 1 is a flow chart of a manufacturing method of a low-shrinkagephotocurable material according to an aspect of the present disclosure.

FIG. 2 is a stress-strain curve diagram of Test 1.

FIG. 3 is a comparison diagram of shrinkage of Test 2.

FIG. 4 is another comparison diagram of shrinkage of Test 2.

FIG. 5 is a comparison diagram of impact value of Test 3.

FIG. 6 is a comparison diagram of hardness of Test 4.

FIG. 7 is a weight loss curve diagram of Test 5.

DETAILED DESCRIPTION

According to an aspect of the present disclosure, a low-shrinkagephotocurable material includes an acrylonitrile butadiene styrene (ABS)resin, a carbon black and a dispersant. The carbon black and thedispersant are mixed with the acrylonitrile butadiene styrene resin. Theweight percentage of the acrylonitrile butadiene styrene resin is85%-99.45%, the weight percentage of the carbon black is 0.05%-5%, andthe weight percentage of the dispersant is 0.5%-10%.

The carbon black can be a surface-modified carbon black material. Forexample, the carbon black can be a carbon black with sulfur, adesulfurized carbon black or other modified carbon blacks. Thedispersant can be a mixture based on methyl methacrylate (MMA) or aderivative thereof, such as ethyl methacrylate (EMA), butyl methacrylate(BMA), 2-ethylhexyl methacrylate (2-EHMA) or a compound based on methylmethacrylate and including specific functional groups. Also, thedispersant can be dimethylacetamide (DMAC) or a mixture withdimethylacetamide.

The aforementioned low-shrinkage photocurable material can be used tomanufacture a physical three-dimensional model. The physicalthree-dimensional model can be post-cured to form a product. Theshrinkage of the physical three-dimensional model in the post-curingprocess can be reduced because the photocurable material includes thecarbon black, which makes the size of the product closer to the originaldesign. Furthermore, the carbon black also helps to improve theproperties such as tensile strength, ductility, malleability, thermalresistance and toughness of the product. On the other hand, thedispersion of the carbon black in the photocurable material can beenhanced by adding the dispersant, and the shrinkage of the product canbe reduced more significantly.

Please refer to FIG. 1. FIG. 1 is a flow chart of a manufacturing methodof the low-shrinkage photocurable material 100 according to an aspect ofthe present disclosure. The manufacturing method of the low-shrinkagephotocurable material 100 includes Step 110, Step 120 and Step 130.

In Step 110, an acrylonitrile butadiene styrene resin is provided. InStep 120, a carbon black solution is provided, and the carbon blacksolution includes a carbon black, a dispersant and a solvent. In Step130, a mixing step is performed to mix the acrylonitrile butadienestyrene resin and the carbon black solution, so as to obtain thelow-shrinkage photocurable material. The types and ratios of theingredients are the same as those in the aforementioned paragraphs, andthe details will not be given herein.

The manufacturing method of the low-shrinkage photocurable material 100can further include Step 121, Step 122, Step 123 and Step 124, toprepare the carbon black used in Step 120 from a carbon black rawmaterial.

In detail, in Step 121, a solution of carbon black raw material isprovided. The solution of carbon black raw material is prepared bymixing the carbon black raw material, 2,4-diisocyanato-1-methyl-benzene(TDI), dibutyltin dilaurate (DBTDL) and dimethylformide (DMF). In Step122, a polyethylene glycol-molecular sieve reactant is provided bykeeping polyethylene glycol (PEG) and dimethylformide in a molecularsieve. For example, polyethylene glycol and dimethylformide can bedehydrated in an environment of low pressure and kept in a 4 Å molecularsieve, to obtain the polyethylene glycol-molecular sieve reactant.

In Step 123, a carbon black pretreating step is performed by mixing andstirring the solution of carbon black raw material, the polyethyleneglycol-molecular sieve reactant and dimethylol propionic acid (DMPA), soas to obtain a substance for purification. The weight ratio of thecarbon black raw material, 2,4-diisocyanato-1-methyl-benzene,polyethylene glycol and dimethylol propionic acid can be 1:10:17:0.6 to1:28:50:2. In this step, 2,4-diisocyanato-1-methyl-benzene, polyethyleneglycol and dimethylol propionic acid can react and form a prepolymer ofpolyurethane (PU), and the prepolymer of polyurethane can further coverthe carbon black raw material.

In the carbon black pretreating step, the solution of carbon black rawmaterial and the polyethylene glycol-molecular sieve reactant can befirst mixed and stirred for a first reaction time, and then dimethylolpropionic acid can be added and stirred for a second reaction time. Thefirst reaction time and the second reaction time both can be 1 hour to 3hours.

In Step 124, a purifying step is performed to purify the substance forpurification obtained from the carbon black pretreating step, so as toobtain the carbon black. In the purifying step, the substance forpurification can be centrifuged to obtain the first precipitate. Thefirst precipitate is mixed with 40 ml of deionized water and intenselystirred with a frequency of 6000 rpm under room temperature for 15minutes, so as to obtain a supernatant. The supernatant is centrifugedto obtain a second precipitate. The second precipitate is washed withacetone and deionized water several times and then vacuum-dried under100° C. for 24 hours to obtain the carbon black.

In the following paragraphs, samples respectively made of “low-shrinkagephotocurable material of present disclosure”, “acrylonitrile butadienestyrene resin” and “acrylonitrile butadiene styrene resin and carbonblack with sulfur” are tested, and the material properties thereof arecompared. First, samples of different manufacturing conditions arenumbered as Table 1 below.

TABLE 1 Manufacturing Conditions of Samples Weight Percentage WeightPercentage Post-Curing of Dispersant of Carbon Black Time Sample No.(MMA) (%) (%) (hr.) Material: Acrylonitrile Butadiene Styrene ResinComparison 1 0 0 0 Comparison 2 0 0 1 Comparison 3 0 0 2 Material:Acrylonitrile Butadiene Styrene Resin and Carbon Black with SulfurComparison 4 0 0.1 1 Comparison 5 0 0.1 2 Material: Low-ShrinkagePhotocurable Material of Present Disclosure (Carbon Black with Sulfur)Example 1 1.5 0.1 0 Example 2 1.5 0.1 1 Example 3 1.5 0.1 2 Material:Low-Shrinkage Photocurable Material of Present Disclosure (DesulfurizedCarbon Black) Example 4 1.5 0.1 0 Example 5 1.5 0.1 1 Example 6 1.5 0.12 Material: Low-Shrinkage Photocurable Material of Present Disclosure(Modified Carbon Black) Example 7 1.5 0.1 0 Example 8 1.5 0.1 1 Example9 1.5 0.1 2

1. Test 1: Tensile Test

In Test 1, the tensile properties of samples made of “acrylonitrilebutadiene styrene resin” and “low-shrinkage photocurable material ofpresent disclosure” are compared with each other. Comparison 2, Example2, Example 5 and Example 8 are tested herein, and the test result isshown in FIG. 2. FIG. 2 is a stress-strain curve diagram of Test 1. Thetest result shows that every sample reaches its yield point when thestress is around 100 MPa. Before reaching the yield points, thedeformations of pulling the samples are elastic. Short, horizontal partsappear in the stress-strain curves after reaching the yield points,where the stress does not change along with the strain and the samplesundergo permanent deformation. As compared with Comparison 2, Example 2and Example 8 have longer horizontal parts after reaching the yieldpoints. In this regard, the samples made of the low-shrinkagephotocurable material of the present disclosure have higher yield pointelongation, which means the low-shrinkage photocurable material of thepresent disclosure will generate higher strain by applying smallerstress thereto and is favorable for industrial processing.

2. Test 2: Shrinkage Test

In Test 2, shrinkages of samples made of “acrylonitrile butadienestyrene resin” and “low-shrinkage photocurable material of presentdisclosure” are compared with each other. Comparison 2, Comparison 3,Example 2, Example 3, Example 5, Example 6, Example 8 and Example 9 aretested herein, and the test result is shown in FIG. 3 and Table 2 below.FIG. 3 is a comparison diagram of shrinkage of Test 2. The test resultshows that the shrinkages of Comparison 2 and Comparison 3 are around 5%and are increased as the post-curing time increased. In comparison, theshrinkages of the aforementioned examples are less than 1%. The resultsprove that by adding the carbon black and the dispersant into thelow-shrinkage photocurable material of the present disclosure, theshrinkages of the samples due to the post-curing process can beeffectively reduced. Moreover, the shrinkages of Example 2 and Example 3are less than other examples, which means the shrinkage problems areimproved with the sulfur elements in the carbon black.

TABLE 2 Shrinkages of Samples Sample No. Shrinkage (%) Comparison 2 4.50Comparison 3 5.60 Example 2 0.02 Example 3 0.02 Example 5 0.40 Example 60.60 Example 8 0.02 Example 9 0.10

Furthermore, in this test, shrinkages of samples made of “acrylonitrilebutadiene styrene resin and carbon black with sulfur” and “low-shrinkagephotocurable material of present disclosure” are also compared with eachother. Shrinkages of Comparison 4, Comparison 5, Example 2 and Example 3are measured and the test result is shown in FIG. 4. FIG. 4 is anothercomparison diagram of shrinkage of Test 2. The test result shows thatthe shrinkages of Comparison 4 and Comparison 5 are 0.12% and 0.11%,respectively. The shrinkages of Example 2 and Example 3 are merely0.02%, which are about 82% less than Comparison 4 and Comparison 5. Itproves that by adding the dispersant into the low-shrinkage photocurablematerial of the present disclosure, the dispersion of the carbon blackis improved and the shrinkages of the samples due to the post-curingprocess are reduced.

3. Test 3: Impact Test

In Test 3, toughness of samples made of “acrylonitrile butadiene styreneresin” and “low-shrinkage photocurable material of present disclosure”are compared with each other. Comparison 1 to Comparison 3 and Example 1to Example 3 are tested herein, and the test result is shown in FIG. 5and Table 3 below. FIG. 5 is a comparison diagram of impact value ofTest 3. The test result shows that the impact value of Example 1 is notgreater than Comparison 1 without post-curing. However, the impactvalues of Example 2 and Example 3 are greater than Comparison 2 andComparison 3 after the post-curing process. The enhancements of impactvalues are more significant as the post-curing time increased, and theconsistency among the samples is also improved (that is, the standarddeviations of impact values decreased). It means that the samples madeof the low-shrinkage photocurable material of the present disclosurehave better impact-resisting properties and consistency, and isfavorable for orthopedics or dentistry as biomedical material with greattoughness.

TABLE 3 Impact Values of Samples Sample No. Impact Value (kgf-m/mm²)Standard Deviation Comparison 1 0.0855 0.020 Comparison 2 0.0873 0.010Comparison 3 0.0776 0.010 Example 1 0.0740 0.005 Example 2 0.0879 0.007Example 3 0.0933 0.001

4. Test 4: Hardness Test

In Test 4, the hardness of samples made of “acrylonitrile butadienestyrene resin” and “low-shrinkage photocurable material of presentdisclosure” are compared with each other. Comparison 1 to Comparison 3and Example 1 to Example 9 are tested herein, and the test result isshown in FIG. 6 and Table 4 below. FIG. 6 is a comparison diagram ofhardness of Test 4. The test result shows that the aforementionedsamples have similar hardness, which proves that the samples stillremains similar hardness to the acrylonitrile butadiene styrene resinwith the addition of the carbon black. It means that the carbon black inthe low-shrinkage photocurable material of the present disclosure doesnot affect the deformation resistance of the samples.

TABLE 4 Hardness of Samples Sample No. Hardness Comparison 1 72.2Comparison 2 77.0 Comparison 3 85.4 Example 1 70.5 Example 2 77.8Example 3 84.6 Example 4 83.6 Example 5 86.8 Example 6 86.4 Example 775.2 Example 8 86.0 Example 9 88.2

5. Test 5: Thermogravimetric Analysis

In Test 5, thermogravimetric analysis on the acrylonitrile butadienestyrene resin and the low-shrinkage photocurable materials of thepresent disclosure including the carbon black with sulfur, thedesulfurized carbon black or the modified carbon black is done. Theanalysis result is shown in FIG. 7. FIG. 7 is a weight loss curvediagram of Test 5. The analysis result shows that the weights of theaforementioned materials are significantly reduced as heated over 300°C. However, the weight of the acrylonitrile butadiene styrene resinstarts to massively lose when the temperature is about 100° C., but theweight retentions of the photocurable materials including the carbonblack with sulfur, the desulfurized carbon black or the modified carbonblack start to decrease obviously until the temperature reaches 150° C.to 175° C. Thus, the thermal resistances of the low-shrinkagephotocurable materials of the present disclosure can be enhanced byadding the carbon black and the dispersant.

In this regard, according to the low-shrinkage photocurable material ofthe present disclosure, the shrinkage of the product after thepost-curing process can be reduced by adding the carbon black. Thetensile strength, ductility, malleability, thermal resistance andtoughness of the product can also be improved. By adding the dispersant,the dispersion of the carbon black in the photocurable material isenhanced. Therefore, the shrinkage of the product after the post-curingprocess is reduced and the properties of the product are maintained dueto the good distribution of the carbon black.

Although the present disclosure has been described in considerabledetail regarding certain embodiments thereof, other embodiments arepossible. Therefore, the spirit and scope of the appended claims shouldnot be limited to the description of the embodiments contained herein.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentdisclosure without departing from the scope or spirit of the disclosure.Given the foregoing, it is intended that the present disclosure covermodifications and variations of this disclosure provided they fallwithin the scope of the following claims.

What is claimed is:
 1. A low-shrinkage photocurable material,comprising: an acrylonitrile butadiene styrene resin; a carbon black;and a dispersant; wherein the carbon black and the dispersant are mixedwith the acrylonitrile butadiene styrene resin, the weight percentage ofthe acrylonitrile butadiene styrene resin is 85%-99.45%, the weightpercentage of the carbon black is 0.05%-5%, and the weight percentage ofthe dispersant is 0.5%-10%.
 2. The low-shrinkage photocurable materialof claim 1, wherein the carbon black is a surface-modified carbon blackmaterial.
 3. The low-shrinkage photocurable material of claim 1, whereinthe dispersant is a methyl methacrylate, a derivative of methylmethacrylate, a mixture with methyl methacrylate, a dimethylacetamide ora mixture with dimethylacetamide.
 4. A manufacturing method of alow-shrinkage photocurable material, comprising: providing anacrylonitrile butadiene styrene resin; providing a carbon black solutioncomprising a carbon black, a dispersant and a solvent; and performing amixing step to mix the acrylonitrile butadiene styrene resin and thecarbon black solution, so as to obtain the low-shrinkage photocurablematerial; wherein the weight percentage of the acrylonitrile butadienestyrene resin is 85%-99.45%, the weight percentage of the carbon blackis 0.05%-5%, and the weight percentage of the dispersant is 0.5%-10%. 5.The manufacturing method of the low-shrinkage photocurable material ofclaim 4, wherein the carbon black is a surface-modified carbon blackmaterial.
 6. The manufacturing method of the low-shrinkage photocurablematerial of claim 4, wherein the dispersant is a methyl methacrylate, aderivative of methyl methacrylate, a mixture with methyl methacrylate, adimethylacetamide or a mixture with dimethylacetamide.
 7. Themanufacturing method of the low-shrinkage photocurable material of claim4, further comprising: providing a solution of carbon black rawmaterial, wherein the solution of carbon black raw material is preparedby mixing a carbon black raw material, a2,4-diisocyanato-1-methyl-benzene, a dibutyltin dilaurate and adimethylformide; providing a polyethylene glycol-molecular sievereactant by keeping a polyethylene glycol and a dimethylformide in amolecular sieve; performing a carbon black pretreating step by mixingand stirring the solution of carbon black raw material, the polyethyleneglycol-molecular sieve reactant and a dimethylol propionic acid, so asto obtain a substance for purification; and performing a purifying stepto purify the substance for purification, so as to obtain the carbonblack.
 8. The manufacturing method of the low-shrinkage photocurablematerial of claim 7, wherein a weight ratio of the carbon black rawmaterial, the 2,4-diisocyanato-1-methyl-benzene, the polyethylene glycoland the dimethylol propionic acid is 1:10:17:0.6 to 1:28:50:2.
 9. Themanufacturing method of the low-shrinkage photocurable material of claim7, wherein the solution of carbon black raw material and thepolyethylene glycol-molecular sieve reactant are first mixed and stirredfor a first reaction time, and then the dimethylol propionic acid isadded and stirred for a second reaction time in the carbon blackpretreating step.
 10. The manufacturing method of the low-shrinkagephotocurable material of claim 9, wherein the first reaction time andthe second reaction time are both 1 hour to 3 hours.